Until evidence to the contrary is available, I would assume that the most likely cause of the problem is that the indexed files are not available locally on the Mac at all times. Make sure the files are set to be available locally (see this entry in the Dropbox Community for guidance).
Thanks, but the files/folders are set to Smart Sync : Local.
There are other indexed filestructures that are added to other DevonThink Databases in Dropbox. These filestructures (which lie side by side) have not been deleted.
The files in DB that are deleted are indexed by DevonThink on machine B.
The files that are NOT deleted are indexed by DevonThink on machine A.
A Devonthink DB that is indexed on Machine A has been added as remote on Machine B. these files were NOT deleted.
check the (local, real) paths to a selection of files which are affected, and a selection of similar but unaffected files; I don’t use Dropbox, so can’t point you to the expected path (but for iCloud it is something like ~/Library/Mobile Documents/com~apple~CloudDocs/FolderName/ rather than iCloud Drive/FolderName/) - see if there are any differences which might point to the root cause of the problem.
Depending on what the path actually is, is it possible the contents are being affected by an automatic offload to iCloud (that would be the setting in the system preferences Apple ID/iCloud Drive Options…/Desktop & Document Folders)?
Give thought to what other differences there are between little Mac A and little Mac B.
When these deletions occur, are both Macs active (so either powered on, or in a sleep mode which allows them to sync Dropbox etc.)?
Are the Macs syncing DEVONthink via Dropbox exclusively, or are you using additional mechanisms (e.g. Bonjour, another cloud provider etc.)? It would certainly be worth following up on whether this problem occurs when the second Mac is completely powered down.
@BLUEFROG No, not yet. I saw there were som problems one year ago that was solved. Its still a mystery why only the folders indexed by Devonthink were affected and not others.
The current hypothesis is that there is a special circumstance as follows:
Computer B has an externally mounted SSD where the Dropbox files are located.
Sometimes in Monterey there is a problem/bug that drops this mount, i.e. dropbox probably sees (some) files that are gone and therefore deletes them.
2a. Not All files are deleted by Dropbox, i.e. files indexed by one devonthink database are deleted.
2.b. I also noticed some files that were deleted were located as sisters to the folders indexed by DevonThink.
All in all, Im buying a new Mac computer så I can store all files without an external SSD drive. Hopefully this will fix the problem.
I don’t have luck with USB drives (spinning and SSD) with my macs. Eventually they all fail on me, mostly probably due to me disconnecting them accidentally or deliberately “too early” without eject. I keep backups of them, and I tend to have to reformat to fix. So I don’t “count” on them without backup,